Make mypy more positive #7368
Description
Maybe someone already noticed this, but IMO mypy is a bit "grumpy". Currently mypy never says anything good to a user. If there are no errors, then the output is just empty. This can even cause some confusion for a new user trying it on a simple clean file.
What do you think about emitting a simple message like Success: no issues found if there are no errors/notes emitted during type checking?
Btw, we can also optionally add a summary line if there are errors saying something like N issues found in M files. I often want to check how many errors there are and this forces me to re-run mypy with | grep error | wc -l.